Lubricant



Patented May 2, 1944 PATENT LUBRICANT Truman E. De Villlers, Okmulgee, Okla, assignor to Cities Service Oil Company, Bartlesville, kla., a corporation of Delaware No Drawing. Application November 7, 1942,

I Serial No. 464,897

14 Claims. (01. 252-34) This invention relates to lubrication and to ing crank case lubricating oils, preventing bearlubricants therefor. More particularly the ining corrosion,,and in increasing the load-carryvention, relates to the stabilization of crank case ing capacity of the lubricating oil.

lubricants with addition agents adapted to in-- The features of the invention will be illustrated hibit oxidation of the lubricating oil, prevent more in detail by reference to certain specific corrosion of crank case bearing surfaces, and examples'and data. Themethod of'manufac- UNETED? increase the load-carrying capacity of the lubrituring certain representative compounds are ilcating oil. lustrated in the following examples:

Various compounds and compositions have 1 been proposed for the stabilization of lubricating Eafampze oils, and it is well-known that unprotected Tri-triethanolamme phosphite, in which each mineral lubricating oils, especially in contact triethanolamine group is attached to phosphorus with air and at elevated temperatures become with an 0-? linkage, was made from triethanodark and produce sludge. Many bearing metals lamine and phosphorus trichloride. 100 cc. of and bearing compositions catalyze thesdeterioraanhydrous ether, 400 cc. of anhydrous benzene, tion of unprotected crank case lubricants under and 45 grams of triethanolamine were placed in the conditions involved in their use. Solvent a 1000 cc. three-necked fiask equipped with a refined petroleum lubricating oils seem \to be reflux condenser including a HCl trap, a mercury somewhat more susceptible to deterioration in sealed stirrer, and a separatory funnel. A mixcrank cases than petroleum lubricants produced ture of 13.7 grams of phosphorus trichloride by other refining methods." In many cases it is in 100 cc. of anhydrous ether was slowly introthe practice to use separate agents to inhibit duced into the flask through the separatory funoxidation and provide extreme pressure charnel. Agitation of the materials in the flask was acteristics. However, according to the present continued throughout the addition of the phosinvention an addition agent has been discovered phorus trichloride and for one hour afterward.

which inhibits oxidation, prevents corrosion of During this time, a white precipitate was bearing surfaces, and also increases the loadformed and was separated out from the solvents. carrying capacity of the lubricating oil. The precipitate was dissolved in about 500 cc.

The primary object therefore of the present of alcohol containing suflicient alcoholic KOH invention is to provide an efiective method of to neutralize the HCl formed. Most of the alcolubrication and to provide a stabilized lubricant hol was then removed from the mixture by disof relatively high load-carrying capacity there tillation, and the resulting KCl filtered ofif. The for. g product was finally freed of alcohol and water Another'object of the invention is to provide in a desiccator under high vacuum at a teman effectively stabilized lubricating oil for the perature of about 160 F. The product was ,found crank cases of automobiles and Diesel engines. to contain approximately the calculated proper- These and other objects are accomplished in tions of phosphorus and nitrogen and to be free of accordance with the present invention by mixchlorine. Analysis showed a phosphorus coning and dissolving a relatively small proportion tent of 5.76%,whereas the calculated value is of an organic tertiary amine phosphite in a 40 6.53%. The nitrogen found in the compound mineral lubricating oil normally subjected to dewas 8.70% while the calculated value is 8.84%. terioration in the presence of oxygen, and normally corrosive to crank case bearings. Emmple N 2 It has been previously proposed that certain Tri-ethanodiethylamine phosphite, in which amine derivatives containing phosphorus be used each amino group is attached to phosphorus by as addition'agents forlubricating oils as shown an O-P linkage, was made from phosphorus by Patent No.-2,146,'543 and'Patent No. 2,146,584, trichloride andethanoldiethylamine. The appaboth-granted on February 7, 1939, but it appears ratus used was the same as that employed in that-all ofthe compounds disclosed in these Example No. 1, 300 cc. of anhydrous benzene patents involve a P-N linkage. The organic 60 being introduced into the flask, after which tertiary amine phosphites of the present invenagitation was started and 80 grams of ethanoldi- 13101111011 the-contrary all contain the linkage ethylamine added. Thereafter while the agita- P0R.N, (R being an alkyl, aryl or alkaryl tion was continued, a mixture of cc. of an group or radical). Compounds of this type have hydrous benzene and 10 grams of phosphorus been found to be unusually effective in stabiliztrichloride was slowly added to the mixture in the flask. The refluxing and stirring was con tinued for two hours, after which about half the benzene was distilled oil. The remainder of the reaction mixture in the flask was then dissolved in alcoholic KOH containing sufiicient KOH to neutralize the H01 formed. The resulting KCl precipitate was filtered oil? and the filtrate transferred to a distillation flask where most of the solvent was stripped 011. More benzene was added to the mixture in the distilling flask. about a liter in all, to completely remove the water. This point was indicated when the distillate came over clear. During the distilling operation care was exercised to avoid complete removal of benzene and overheating of the material in'the flask, the last traces of benzene being removed, however, along with unreacted amine in a vacuum desiccator at about 160 F. The product was found to contain 7.89% of phosphorus where the calculated value is 8.18%, and to contain 11.58% of nitrogen where the calculated value is 11.08%.

Example No. 3

' tillation. The distillation of the benzene carried off the remaining H01 gas which was separated from the condensed benzene, the latter being returned to the flask to eflect the stripping out of the HCl from the reaction mixture comprising dicresyl phosphorus chloride and benzene.

The reaction mixture in the flask was reduced so that it contained only about 200 cc. of benzene and was then added to another flask containing 200 cc. of benzene and 55 grams *of triethanolamine. This mixture was refluxed with agitation for one hour. An oily layer separated at the bottom of the mixture, and was removed. The water and benzene content of the product was removed in a vacuum desiccator at about 160 F. The product was found to contain no halogen, 8.88% phosphorus, and 1.39% nitrogen. The calculated values for phosphorus and nitrogen are 7.89% and 3.56% respectively. The high value for phosphorus and the low value for nitrogen indicates that the product is amixture and probably contains compounds in which two, or possibly three dicresyl phosphite groups, --P(OR)2, are attached to a single triethanolamine group by O-P linkages. Such compounds may be illustrated by the general formulat The efiectiveness of the addition agents of the present invention is illustrated by the data produced below in tests carried out on the compounds of f the foregoing examples. These compounds were blended with a Mid-Contiusage nent solvent extracted 30 S. A. E. lubricating oil, having a Saybolt Universal viscosity at 210 F. of 62.7 seconds. The following table shows the results obtained on the Underwood testing 5 apparatus, the 011 along being run only 20 hours as against 50 hours for the blends. In the table the addition agent in each blend is referred to by the number of the example above, by which it was produced.

1 as"? are is"? aone o o o- Nofi N632 Nets Duration oitest. 20hrs '60hrs-.... 50h Copger baflle: H

orrosion Medium Verylight. Medium Verylight. Lacquer deposit. do do .do..-- None. 'He ater rods: Oorrodo. None.-.. Light.-- Do.

son. Bearing; (cadmium- 1.658... 0.000 0.007...- 0.000.

silvlelrJ loss in we ms. Con tion oi oil sludge, mgJiO g.: lohrs'. 13 14 11. 20hr6 1,099.--- 17 15 10. hra 1B 18 11. gfirs 14 9. rs 16 20 Neutralization No. 10

(electrometrio at pH 11.0):

3. mommy Other portions of the same 011 and of the com-. positions tested in the Underwood oxidation-ap- 1 the Comeli (Falex) testing machine with the results shown in the 101- paratus were also tested in 40 lowing table:

Oil Oil- Oil 81 at. ti t 0 7 i one 0 o o 40 No. 1 No. 2 No. 8' 1 Temperature:

Start "F .98 so. as was Finis ,F 178 240 250 272 J aw load-torque i 5 2501175 3 3 3 2 6001bs 7 8 5 '0 750lbs 12 12 13 10 1,0001bs 18 18 21-70 10 1,250 s--. d 22 2a 21 1,5001bs... 25 138 26 2,000 a... so 42- -31 2,500lbss1- 41 55 3,000 s- 37 68 51' 3,500 5. 42 67 03 4,000 s. 54 78 .74 4,500lbs.-- 80 00* 78 Failure at 1, 260 N o 1 1,000 N0 ear: Pin Med. Med. Scar 81 t 0 Bushings .inches-. Me ta Wi 3'. 0

1 Slight seizure producing scar ioilowed by carrying iull In the Underwood tests on the solvent extracted oil without the addition agent, the bearing-cob" elapsed, and the ten-hour period. The ability of the compounds of thepres ent invention to protect the bearings against-- corrosion is strikingly illustrated by the complete protection obtained in spite of the fact that the neutralization numbers. went up considerably in" roslon started before ten hours had had progressed considerably at the cases of agents numbers 1 and 2, as the tests proceeded.

The addition agents of the present invention- 7'; are especially effective with, and are preferably used with petroleum lubricating oils refined by solvent extraction methods. They are also useful and beneficial in any crankcase lubricant regardless of its'orignr or of the method by which it is refined. The proportionotthe addition agent may vary from 0.05% to ofthe'lubri-n eating oil stock and may be admixed therewith in the form of a concentrate in a mutual solvent. In certain cases the use of a concentrate in a solvent is preferred because certain of the compounds such as those containing a number of OH radicals are not very soluble in the lubricating oil stock. So far, however, no difficulty has been encountered in dissolving the relatively small proportions as for example 0.5% of the agent in the lubricating oil.

From the foregoing description of the invention taken in connection with the examples and data presented, it will be apparent that since all compounds coming within the scope of the invention are tri-valent phosphites and include the group P-ORN, the number of possible compounds is rather limited. However, certain variations are possible as illustrated by the compounds of the examples. The compound may inl.

clude the group --ORNR'2, either one, two or three times, and that where only one or two such groups are included in the compound, it may also include respectively two or one -OR group attached to phosphorus. The R radicals in this compound may be alkyl, aryl, alkaryl, hydroxy alkyl, hydroxy aryl, or hydroxy alkaryl. In certain special instances, the compound may be a polymer-type derivative containing two or more of the groups P-ORNR'2 linked together in the manner indicated above in Example No. 3.

The examples and data given above are for purposes of illustration, and it is not intended that the invention shall be limited thereby, the i vention being defined by the claims and limited only by the scope of the invention and the prior art.

Having thus described the invention in its preferred form, and illustrated the same in connection with certain specific examples, what is claimed as new is:

l. A crank case lubricating oil composition comprising a relatively large proportion of a solvent refined mineral lubricating oil normally tending to deteriorate and corrode the bearings of the crank case under conditions of normal use and a relatively small proportion of an oil-soluble stabilizing agent admixed therewith sufficient to in-' hibit such deterioration and prevent such corroson, said agent comprising a tri-triaikanolamine phosphite, said composition being further characterized by a relatively high stability toward dcterioration by oxidation under the conditions of normal use in the presence of the metals of the crank case.

2. A crank case lubricating oil composition as defined by claim 1 in which said phosphite is tritriethanolamine phosphite.

3. A lubricating oil composition comprising a relatively large proportion of a refined mineral lubricating oil having dissolved therein a relatively small but sufficient proportion of an oxidation and corrosion inhibiting agent, comprising an organic phosphite containing the group P--ORNR'2 in which R is an organic radical se lected from the group consisting of alkyl, aryl, and alkaryl radicals, and R is an organic radical selected from the group consisting of alkyl, aryl, alkaryl, hydroxy alkyl, hydroxy aryl and hydroxy alkaryl radicals.

4. A lubricating oil, composition as defined by claim 3 in which said phosphite has the general formula P(ORNR2) a.

5. A lubricating oil composition as defined by claim 3 in which said phosphite has the general formula ROP(ORNR2) 2. I

6. A lubricating oil composition as defined by claim 3 in which said phosphite has a general formula (RO)2PORNR2.

7. A lubricant comprising a relatively large proportion of a mineral lubricating oil and a relatively small but efiective proportion of a product of the reaction between phosphorus trichloride and a tertiary organic amine as an oxidation inhibitor.

8. A'lubricant comprising a relatively large proportion of a mineral lubricating oil refined by solvent extraction and a relatively small but effective proportion of an oxidation inhibitor comprising the reaction product produced by reacting phosphorous trichloride with a tertiary organic amine containing an OH group included in at least one of its organic groups.

9. A lubricant comprising a relatively large proportion of a mineral lubricating oil and a relatively small but effective proportion of an oxida tion inhibitor comprising an organic phosphite containing the group P-ORNR'z, in which R is an organic radical selected from the group consisting of alkyl, aryl, and alkaryl radicals, and R is an organic radical selected from the group consisting of alkyl, aryl, alkaryl, hydroxy alkyl, hydroxy aryl and hydroxy alkaryl radicals.

10. A crank case lubricant consisting almost entirely of a refined mineral lubricating oil and a relatively small but effective proportion of an oxidation and corrosion inhibitor comprising tritriethanolamine phosphite.

11. A stabilized crank case lubricant consisting essentially of a refined mineral lubricating oil having dissolved therein from 0.02% to 5% of an organic tri-ester of tri-valent phosphorus, in which at least one ester group is an organic tertiary amine.

12. A lubricant as defined by claim 11 in which at least one ester group is o-cresol.

13. A lubricant comprising a relatively large proportion of a mineral lubricating oil and a. relatively small but sufiiclent proportion of an oxidation and corrosion inhibitor comprising a tri-ester of phosphorous acid in which each of the ester groups is an organic tertiary amine.

14. A lubricant comprising a relatively large proportion of a mineral lubricating oil and a relatively small but sufiicient proportion of an oxidation and corrosion inhibitor comprising a. tritrialkanolamine phosphite.

TRUMAN E. DE VILLIERS. 

